Deuterium is a hydrogen isotope of mass 2, and is commonly identified by the symbol D. Deuterium occurs in nature as a diatomic molecule, or in compounds.
Deuterium arc lamps are known in the prior art, principally because of their ability to generate light in the ultraviolet range. In general, there are three regions of the ultraviolet spectra. These are known as "UVA", "UVB" and "UVC". Deuterium lamps are known to produce light in all three regions, and are therefore commonly used in various spectral analyzers, such as absorption detectors, spectral photometers, spectroscopes, and the like.
Deuterium lamps have an anode and a cathode arranged within an elongated tubular envelope made of glass or ultraviolet-transmissive material. An electron stream is caused to flow from the cathode to the anode. This is shaped by a baffle, and a "ball of fire" is produced adjacent the baffle to generate light in the ultraviolet range. In many cases, the mechanical structure (e.g., anode, baffle, and the like) is cantilever-mounted within the glass envelope on the distal end of one or more electrical conductors. The conductor itself is generally in the form of a rod-like member having a large length-to-diameter ratio, but normally possesses sufficient strength to prevent or restrain axial movement of the mechanical structure within the envelope. In prior art lamps, the stem of the lamp was typically penetrated by several conductors. Some of these were provided to hold mechanical structure in place, and were not required for electrical conduction.
It is normally desired that the aforesaid mechanical structure be spaced centrally within the envelope and away from the side walls of same. If mounted as a cantilever, the mechanical structure may cause the conductor to flex or bend during movement. This is particularly true with a recent advent of portable applications for such spectral analyzers. There is also a drive towards miniaturization of devices employing deuterium lamps, with a concomitant desire to reduce the size of the lamp itself. To the extent that the conductor must be reduced in size, the possibility of flexure of the structure-supporting anode becomes of increasing concern as the rod diameter is further reduced. Moreover, it is pointed out that the mass of the structure supported at the distal end of the conductor is large in relation to the mass of the conductor itself.
Additional details of prior art deuterium lamps are shown in a catalog entitled "Deuterium Lamps and Power Supplies for UV Analytical Instruments", Imaging and Sensing Technology Corporation, Horseheads, N.Y. (undated), and in U.S. Pat. Nos. 4,433,265, 4,910,431, 5,117,150 and 5,552,669. The aggregate disclosures of these various prior art references are hereby incorporated by reference. These references appear to disclose various types of prior art deuterium lamps in which mechanical structures are cantilever-mounted on the distal end of a conductor.
Accordingly, it would be generally desirable to restrain lateral movement of the cantilevered structure so as to avoid unnecessary flexure of the conductor and to permit miniaturization of deuterium lamps and devices employing same.